Summary

So after downloading some of the power supply covers on here and on some other sites NONE actually fit 100% or the people that did the designs tried to over complicate their designs as flip covers and then getting their measurements incorrect by adding swing hinge clips and screw holes that need to line up with existing holes in the PSU... Like I said none of these really do fit as when you have to scale them when slicing it comes out of proportion and its not working.

I had a specific Power rocker switch with fuse that I wanted to use.
So I designed this very crudely but very functional with the Official Anet Logo to boot.

The hole I drilled for the top screw of the switch BY ACCIDENT aligned 100% with an existing hole in the PSU.

Apart from that one screw that holds the cover in place I used 2 small pieces of double side foam tape on the front top to keep the cover in place.

Print Settings (note these settings are with Craftware)

Printer: Anet A6
Rafts: Doesn't Matter
Supports: Yes
Resolution: High
Infill: 15%

Notes:

Please note that these are Craftware settings and I have no idea what they would be on cura as personally I don't like Cura or simplify as simplify is anything but simple lol.
i did use support but maybe you would not need to as i did decide to print it with the logo face down to give the front face a very smooth look.

Heatbed @ 50 degrees C
Nozzle Head @ 200 degrees C